Deep well pump



May 13, 1958 Filed Aug. l5, 1955 R. W. SCHOEN DEEP WELL PUMP .3Sheets-Sheet 1 May 13, 1958 R. W. SCHOEN DEEP WELL PUMP Filed Aug. 13,1953 AN IK 5 Sheets-Sheet 2 R. W. SCHOEN DEEP WELL PUMP May 13, 195s 5Sheets-Sheet 3 Filed Aug. l5, 1953 United States Patent DEEP WELL PUMPRoger W. Schoen, Mineral Wells, Tex., assignor to Alco Valve Company,University City, Mo., a corporation of Missouri Application August 13,1953, Serial No. 373,955

Claims. (Cl. 103-46) The present invention relates to a deep well pump,and especially a pump of the hydraulic type actuated by a column ofpower oil conducted from the surface down to the bottom of the well, atwhich latter point the pump is located, and which pump includes p istonmeans and valving mechanisms that alternately port pressure from thepower oil to and from one face of the power piston, so as to produce thereciprocating movement of the pump rod.

it is an object of the invention to improve the pumping mechanism so asto enable it to be contained within a smaller space than heretofore.Another object is to provide a pump of this kind which may be assembledand disassembled readily with a minimum number of tools of a minimumnumber of different characteristics.

A further object is to provide a reversing valve mechanism assembled7with the pumping mechanism so that there is a mechanical reversing ofthe reversing valve mechanism at the end of each stroke of the piston.Also, it is an object to provide a pump mechanism that will not stop on-dead center, but rather is stall-proof.

Another object is to have a pump with relatively slow pump stroke andrelatively fast return.

Other objects will appear from the fuller description to follow:-

ln the drawings:

Figures 1 through 5 represent successively lower parts of the pump motorand pump mechanism at the bottom of the well, shown in verticaldiametrical section, there being some overlap in the several views so asto assure completeness of disclosure;

Figure 6 is a transverse section on the line 6 6 at the top of Figure 1(in all the transverse sectional views the well tubing is omitted);

Figure 7 is a transverse section on the line 7-7 o Figure l;

Figure 8 is a transverse section on the line 8 8 of Figure 1;

Figure 9 is a view partly in section of the upper head .of the pump;

Figure 10 is a transverse section on the line 10-10 of Figure l;

Figure 11 is a somewhat diagrammatic view of the valving apparatus thatappears in the lower half of Figure 1;

Figure 12 is a transverse section on the line 12--12 at the top ofFigure 2;

Figure 13 is a transverse section on the line 13--13 of Figure 2;

Figure 14 is a bottom plan view of a spacer and sealer member at thelower end of the valve mechanism;

Figure 15 is a vertical section of the spacer and sealer taken on theline 15-15 of Figure 14;

Figure 16 is a transverse section through the pump taken on the line16--16 at the upper part of Figure 2;

Figure 17 is a transverse section on the line 17-17 of Figure 2; and

Figure 18 is a transverse section on the line 18`18 of Figure 2.

2,834,294- Patented May 13, 1958 rice . The pump will be described as anoil pump, with the understanding that other fluids may be used. A welltubing T has been illustrated to show the disposition of the pump, thepump being inserted into the tubing and lowered down from the surface.The diameter of the tubing has been exaggerated for clarity in drawing.As is known in this type of pump, a power fluid tube 20 leads down fromthe surface to conduct power oil down, which power oil is put underpressure by an appropriate pressure generating mechanism at the surface,of which various types are known in the art; such as that illustrated inthe application of John E. Dube and Roger W. Schoen, Serial No. 374,004led Aug. 13, 1953.

The power oil tube 20 is connected into the head 21 of the pump motormechanism. This head, in turn, is threaded into the upper end of anouter barrel `22 that extends downwardly so that it may enclose thevalving apparatus and the power piston motor apparatus for the pump. Thelower end of the outer barrel 22 connects through a threadedly removableclosure 23 into a compound spacer device consisting of spacer tubes 24and 241 adjustably connected together. The spacer tube 241 finally isthreaded onto the upper end of one of the standard sucker rod pumps,here generally indicated at 25. Since this pump forms no part of theinvention, which is primarily concerned with the power mechanism toreciprocate the pumps, the pump itself will not be described. Sufce itto say that a sucker pump pull rod 26 extends upwardly from the top ofthe sucker rod pump 2S and constitutes the piston or plunger rod of thesucker rod pump, which is reciprocated up and down so as to cause theoil to be lifted. The upper part of the pump 25, as it appears in Figure5, has openings 28 that constitute the oil outlets by which the pumpedoil is delivered into the well tubing T upon the successive strokes ofthe pump, to be conducted to the surface. It is, of course, well knownin this art that there is some sort of sealing means between the oilbeing pumped to the surface and the well oil at the bottom of the pump.

The pull rod 26 is threaded at its upper end into a coupling 30 that, inturn, is threaded into the lower end of a tubular connecting rod 31. Theupper end of the connecting rod 31 connects into a piston assembly.Actually, the upper end of the connecting rod 31 ts through the lowerend of a fitting 32, which has an enlarged opening extending downwardlyfrom its upper end to provide a shoulder to receive and hold aninternally threaded ring 33 removably threaded onto the threaded end ofthe connecting rod 31. It will keep the connecting rod from pullingdownwardly out of the union 32. Above the ring 33 there is anothercoupling 34 externally threaded into the upper open end of the union.33, so that it keeps the connecting rod from moving out of the upperend of the iitting 32. In turn, the upper end of the member 34 receivesthe lower end of a pipe 35, which latter is threaded into the member 34.

The upper end of the pipe 35 is threaded into a ring nut 36 which clampsa piston device 37 onto the pipe 35 between the member 34 and the ringnut 36. The piston device may be of any suitable construction orassembly. Above the nut 36 a coupling 38 is threaded onto the upper endof the tube 3S. Its upper end, in turn, is threaded into a spring barrelelement 39 for a purpose to appear.

The foregoing parts reciprocate with the sucker rod pump piston andprovide an axial opening from the upper end of the cage 39 to the bottomend of the connecting rod 31.

The cage 39 is a part of an overtravel spring mechanism including a coiltype overtravel spring 44) acting at its lower end against a retainer 41of a cross-sectional shape illustrated in Figure 18. The upper end ofthe spring Taasafgeee 4) acts against a'shifter device 4H) which isprovided with a shoulder 42, by means of whichit-is-retainedein theupper end of the overtravel spring cage 39.

Except in cases of overtravel, the shifter device 410 will reciprocate.with the connecting rodjarid'hhce Y'with the sucker pump. ,y

Reverting to the lower end of the-apparatus, as pr''viously indicated,there is an adjustable tubular extension of the outer barrel 22 formedby the fmer'nbers 24 yand 241, with which the sucker rod pump 25 isconnected by the illustrated connections. JThis adjustable barrel, intunpis threaded onto the connecting rod barrel 24. The adjustable barrelextension may regulate the relative positions between the sucker rodvpiston and cylinder (not shown), and the motor piston, to insuremaximum sucker rod piston stroke.

The upper end of the spacer tube 241 has an extended internallylthreaded portion that receives the externally threaded lower end of theupper member 24. By this arrangement, the upper member 24 may bethreaded yinto the lower vmember 241 a selected distance, after whichthe relative positions may be locked by a ring nut 43.

The upper end of the spacer tube 24 is threaded onto the retainer andclosure 23. Thereis appropriate packing surrounding the connecting rod31 inthe lower end of this retainer 23, and there is additional packinglikewise arranged at the upper end. Chevron packing is preferred for theupper packing.

An upper packing retainer and sealer 44 lits into the upper end of theretainer 23 and also is stabilized and `sealed within the barrel 22.Suitable O-ring packing elements are provided at various points in theassembly as indicated.

The upper lend of the retainer 44 fits into the lower end'of an innercylindrical barrel 46, and is causedto close the lower end thereof, bythe retainer 23. The barrel 46 abuts on a tirm packing 47; and itextends upwardly to form-the cylinder for the piston 37. The innerbarrel 46 likewise extends upwardly past the overtravel spring cage 39and, at its upper end, seats around the lower reduced end of a centeringspring cage 48, there being a suitable O-ring packing between the two,and the two also fitting firmly to transmit compressive-forces axiallybetween the two, with suieient axial contact to resist lateraldistortion of the assembly under compressive stress, which is likewisetrue of the fitting of the lower closure 44 and vthe inner barrel.

The centering spring cage 48'extends upwardly'and, at

its upper end, receives asealing and spacing member 50I t, that `appearsin Figure 2k and separately in Figures 14 and 15. The centering springcage 48 has a recess extending down from its upper end, which isshouldered at` its lower end so as to receive the spacer 50, and providesecure tit preventing lateral distortion under compression, The `spacer50 has"afplurality of projections or feet 52 extending downwardly fromits lower surface. These projections have a somewhat lesser diameterthan the main body of the spacer, so thatthey extend into the centeringspring cage 48 belowy the shoulder. rThese feet portions 52 areseparated so as to permit uid'ow, as will appear. The spacer 50 also hasa plurality of more or less semi-cylindrical cut-outs 53 that extendvertically between the several feet 52, all for purposes 4to appear.

The upper end of the spacer member 50- hasfsimilar feet-like projections54, but these extend cut to the-diam eter of the spacer, and therebyV tinto a valve cylinder 55 so that the latter extends down onto thespacer' 50-and yet so that there may be uid ow assured attheitop of thespacer 50 from the middley thereof to the surface of the cylinder 55.The cylinder S has a sealingt'- nto the spacer 50 to resist lateraldistortion under compression on the assembly.

Thecylinder 55, which surrounds the valving 'inecha- A nismand ispermanently and solidly'lit'ted 'ontota valve' y going parts.

body 56, extends upwardly and tits over and engages in abutting relation4the upper head 21 of the pump device which is reduced in diameterwithin the outer barrel 22. As a matter of fact, reference to Figures land 8 will show that there is a double reduction on the lower end of thehead 21 so that the cylinder 55 will be spaced within the barrel 22.

Suitable O-rings as indicated may seal off the fore- The structure lasdescribed shows that the pump 25 is rigid with the spacer tube 241, andthe latter is rigid with the lspacer tube 24, once those two parts aresecured in proper adjusted relationship. In turn, the `spacer tube 24 isrigid with the packing retainer and closure 23 ywhich,'in turn, is rigidwith the outer barrel 22, and the latteris rigid with the upper head 21.

Thus, if the foregoing parts are threaded tightly together, they willinsure against change in the length of the pump structure.

'Inside the'foregoing barrel part, the packing retainer 23 and its upperpacking head'44 are in ixed abutting relationship so that the member 44can not move downwardly when the parts are secured together asaforesaid. Thenthe inner barrel 46 is in abutting relationship with thecentering spring cage 48, and the latter is in abutting relationshipwith the spacer 56 which, in turn, abuts thevalve lcylinder 55,'whichlatter is in abutting relationship withthe upper valve head 21. We maycomment thatthe valve body member 56 is also in abutting relationshipywith'the spacer Sil and with the upper pump head 21. Allof these partshave suflicient overlap to provide stability against lateral distortionwhen the upper headand lower closure 23 are tightened onto the outerbarrel. 'Howev'er, the space between the outer and inner barrelsissmall7 and even the distortion permitted by the=out`er`barrel would notseriously interfere with the pump.

lFrom the-foregoing, when the upper pump head 21 is threaded intoposition in the barrel 22, the inner parts mentioned are rigid and areheld against extending lengthwise.

By the foregoing arrangement, the parts may be secured together, but'also maybe readily disassembled with a minimum number of tools. v

The spacer 241 has lateral ports 60 at its lower end which open into thewell casing. There are other ports 62 of'like'eharacter through theupper spacer tube 24, a'nd'at Vthe top of the latter there are stillmore ports 63. This assures against the development of a conned spacewhich could ll with oil and resist pump action. There'canv be no trappedoil within the spacer Vtubes/'around the connecting rod 31.

The lower spacer tube 241 is provided'with opposed grooves 64 that areflats designed to permit application rolf a tool to this part for aid indctaching it from the associated parts.

Reference to Figures 2 and 3 will show that the inner barrel 46'is'spaced inside the outer barrel 22 so that oil may p ass between thetwo. The lower end of the inner barrel 46 lhas ports 66 so that such oilmay flow into an annular space 67 forming a lower pressure chamber, andmayfact'against a lower annular surface 68 on the member 32, whichlatter is assembled with the piston elcments-37so as to constitute withthem a piston. The member 32 is slightly smaller than the inside of theinner barrel 46 and oil may iow around between these two parts until itreaches the piston member 37. This piston member-maybe 'an assembly ofseparate parts, if desired, but is shown as asingle member. vThe totaleffective .lowerpiston'area, therefore, consists of an annulus, with theouter diameter equal to the inner diameter of the inner barrel'46, andits innerdiameter equal to the outer diameter of the connecting rod 31.

The upperpressure or piston chamber 7i' is within the'nner barrel 46above the piston. The upper surface 72- of the ovcrcenter'spr'ing' cage39 'constitutesone part of the downstroke piston. area. As noted, theactuator 41 does not have a tight t with the lassociated elements, sothat the oil may pass down within this part as well as within theovercenter spring cage 39. The retainer 41 has a plurality of more orless semi-cylindrical passages 74 (FiguresZ and 18) through it so thatthe oil may flow down into the vinterior of the hollow tube 35 that, ineffect, constitutes the upper part of the connecting rod 31. Since theseparts are secured together and have a common bore, this liquid maycontinue down until it reaches 'the head of the union member 30 whichconfines it at the bottom end of the hollow connecting rod 31. The totaleffective piston area for the top of the piston is the inner diameter ofthe inner cylinder 46.

It will be seen from the foregoing that the lower cylinder 67 is alwaysin communication, with the space or passage 70 between the outer andinner barrels. This passage 70 continues upwardly inside the outerbarrel 22, past the inner barrel 46, the cage 48, the fitting 50 and thevalve shell 55, to the head 21, where it communicates directly with thepower uid pipe. This latter is accomplished by connection of the latterinto a well 80 in the head 21, from which two passages 81 (Figuresl, 6,8 and 9) extend downwardly and laterally to the reduced portion of thehead 21, above the valve shell 55, which is the upper closure for thepassage 70.

Assuming for the moment the same hydraulic pressure to exist in thecylinders 67 and 71, the piston would be driven downwardly because ofthe greater effective area on the upper side of the piston than on thelower side. This has been diagrammatically suggested by the arrows inthetwo pressure cylinders, with the broken line extended across the uppercylinder 71 to illustrate the larger piston area for the downstroke.This is evident because the lower area is merely the annular spacebetween the connecting rod 31 and the barrel 46, whereas the` top areaproducing the downstroke is the entire inner diameter of the barrel 46.The valving mechanism is designed to determine when the hydraulicpressure shall be admitted to both of these cylinders and when thepressure in the upper cylinder shall be exhausted.

In considering the valving mechanism, it is convenient to start at thetop. The head 21 also includes so-called exhaust passages 85 that leadinto the well casing so as to communicate with the oil being pumped orthe production oil. These passages open through the bottom of the head21, which head is provided with spaced feet 87 so that, although it isin contact with the upper surface of the valve body 56, itnevertheless'does not obstruct the ow of fluid from the passages 85outwardly and downwardly. As appears particularly in Figures l and l0,the valve body 56 in its upper end has two peripheral grooves 89extending down for a certain distance whence they communicate withlateral ports 90 leading to the axial bore 91 through the valve bodyfrom end to end. Owing to the various and separate feet 87 on the bottomof the head 21, the particular orientation about its axis of the valvebody 56 with respect to the head 21 is immaterial. There may always beoil flow communication between the passages 89 and 85.

The upper pressure cylinder 71 connects through a partition 93 in thecentering spring cage 48. This partition 93 is shown in Figures 2 and17. It has a plurality of holes 94 through it, so that it does notobstruct passage of Huid from the cylinder 71.

Above the partition is the centering spring chamber 95, the details ofwhich are to be described. The centering spring chamber 975 is incontinuous communication past the feet 52 on the sealing member 50, andthence vertically through the passages 53 and around the upper lugs 54,so as to be in constant communication with the lower end of the valvebody 56.

t While the valve, as such, is not a part of this present invention, itsadaptation into this assembly is a part hereof. It need be describedonly diagrammatically insofar Gf as the particular construction of itsprtings is concerned.

Figure l shows that the pressure oil passage 70 outside the valvecylinder 55 communicates through the cylinder 55 and the valve bodyitself at three points. The lowest of these is the passages 1110'. Themiddle one is the passages 101. And the upper one is the passages 1112.By this arrangement, oil under pressure is always admitted into thecentral bore 91 of the valve body 56.

There are three valves in the axial bore 91 of the valve body 56. Forthis reason, there are two stop mem-- bers pinned into the valve body.There is a lower stop member that seals olf the bottom part of the borefrom the intermediate part. This stop 105 is held in place by a pin 106.There is also a stop seal 1117 held in by a pin 108. The seal and stop167 separates the intermediate valve chamber from the upper valvechamber. These stops separate three separate hydraulic valve systems.

Within the bottom valve chamber there is a mechanical valve 110. It hasa depending valve stem and head that is latched into a Valve stemextension 111. To this end, the lower end of the valve has a reducedneck 112 and a head 113. The extension 111 has an enlarged head 114,having a recess for the head 113 in the reduced stem 112, with a lateralopening 115 to receive the stem 112, and a larger lateral opening 116 toreceive the head113. By this means the extension 111 may readily belaterally passed onto the valve head, and yet held so that movement upor down of the extension 111 causes corresponding movement of the valve.The iit of the head 114 within the fitting 50 prevents lateral detachingmovement of these parts when they are in operating positions.

The member 111 extends down through the partition 93 and is joined toanother valve stern extension 120 by means of a threaded collar 121engaged over the lower threaded end of the member 111 and the upperthreaded end of the extension 120. In the positions illustrated, thecollar 121 passes freely through a center opening in the partition 93.The collar forms abutments for purposes to appear.

The stem extends down freely through the actuator 41 in la mannersufficient to permit the passage of oil between the two. It has a lengthapproximately equal to the stroke of the pump motor piston. At its lowerend the member 120 is provided with a double nut 122- 123 tightlysecured to the end of the extension stem 120 so as to provide anadjustable shoulder abutment element for a purpose to appear. Figure 18shows that the retainer 41 tits reasonably closely with a sliding fitonto the stem extension 120 so that the nut 123 may act as an abutmentagainst the bottom surface of the retainer 41. The lower end of thevalve stem 120 and the locking nuts 122 and 123 may move freely withinthe tube 35 of the piston, the

lunion 34 and the connecting rod 31.

The centering spring chamber 9S contains spring actuated centeringmechanism for the mechanical valve 110. There are two anged, tubular,centering spring guides. The lower guide 125 rests on the upper end ofthe partition 93 without obstructing the vertical passages 94,

therethrough. The lower end of a coil spring 126 rests on the guide 125.The upper end of the coil spring 126 rests on the upper guide 127 whichimpinges upon the feet 52 on the bottom of the spacer, which feet areprovided soI as to vassure flow through the passages 53 and around theguide 127. The spring 126 is a compression spring normally urging thetwo guides 125 and 127 apart and into contact with the partition 93 andthe spacer 50, respectively. The stem extension 111 passes through theguides and the spring. The head 114 and the upper end of the collar 121are spaced Iapart a distance equal to the distance between the spacer 50and the partition 93, so thatl the valve stem 110-111-120 is yieldablyheld in a middle position from which it may be dipslaced in eitherdirection, and toward which it will be urged to return by the spring126.

The valve 110 has four lands thereon. They are, reading from bottom totop, the lands 130, 131, 132 and 133. Between the lands 130 and 131there is a valve passage 134. Between the lands 131 and 132 there is avalve passage 135. Between the lands 132 and 133 there is a valvepassage 136.

Below die land 130 the valve is openV to the pressure within the uppercylinder 71. The space above the land 133 between it and the spacer 105is similarly connected to the cylinder 71 by passages 13S. v

At this point, it is observed that the passage 138 is not illustratedcompletely, but is shown fragmentarily in a manner to indicate itspresence. Actually, the passage extends to the surface-of the valve bodymember 56, and thence by a groove on the valve bodyk member that isenclosed by the cylinder 55. This groove extends parallel to the axisdown to the space below the valve body. A dashed line indicates it. Itwill be seen that this dashed line also connects into a passage markedCYL, at the upper end of the valve body.

By the foregoing arrangement, the two opposite ends of the valve arealways open to the pressure existing in the upper cylinder 71,

The mechanical valve `110 is designed to have three positions. It isillustrated in its intermediate or neutral position into which it isnormally moved by the action of the centering spring 126. If the valvestem 120 is pushed upwardly, the collar 121 will impinge upon the lowerguide 125, elevating the same against the spring 126 and causing thevalve 110 to move to an upper position. In like fashion, if the valvestem 120 is pulled downwardly, it will, acting on the head of theextension 111, pull the upper guide 127 down, compressing the spring 126and moving the valve 110 to a lower position.

In the middle position or neutral position illustrated in Figure 11,power oil is introduced by the passages 100 into the space 135, where itis trapped. Also, the oil at the pressure of the production oil in theinterior of the well casing and carried down by the passages 85 istransmitted from above the valve body'56 through the passage 140 shownin Figure l0 and shown by a dashed line in Figure l1, to two passages141 and 142 leading respectively to the valve spaces 134 and 136, inboth of which it is then trapped.

If the mechanical valve 110 is moved upwardly until the two guides 125and 127 abut, it will connect the power oil passage 100 through thevalve passage 135 to work passages 143 that lead, as indicated by adotted line, up wardly to the lower pressure chamber belowthe'intermediate valve. At the same time, the upward movement of themechanical valve 110 will cause the return line 141 to be connectedthrough the valve space 134 to a passage 144 that is connected, asillustrated by the dotand dash line, into the upper pressure chamber ofthe intermediate valve. Hence, such shifting of the mechanical valveports pressure or power oil to the bottom of the intermediate valve andconnects the upper end thereof to exhaust. A consideration of theporting conditions when the valve 110 is lowered, until the two guides125 and 127 lare in contact, will demonstrate that the reverse portingof power oil onto the upper part of the intermediate valve andproduction oil pressure on the lower part will be produced. Also,whenever the mechanical valve 110 returns to neutral position, ithydraulically locks the pressures in the intermediate valve pressurechambers.

Power oil is continuously supplied through the ports 101 to theintermediate valve 150. The intermediate valve has four lands 151, 152,153 and 154. These afford, respectively, a lower valve passage 155, amiddle valve passage 156, and an upper valve passage 157. They alsoprovide for upper Iand lower valve operating chambersconnectedrespectively to the lines 143 and 144 that are controlled by themechanical valve soas to position` the intermediate valve, :asdescribed. It is a two-'position valve, illustrated in its lowerposition. Its primary function is to position the upper main valve byregulating the connections into the chambers above and belowthis valve.And it functions to produce a relatively rapid action of the upper valveor main valve, avoiding its sticking in a mid-position.

In the lower position of the intermediate valve 150, illustrated, poweroil enters the passages 101 and llows by the valve passage 156 topassages 160 that lead to the lower pressure chamber below the topvalve. Meanwhile, the valve space 157 connects the passage 161 leadingfrom the upper pressure chamber of the main valve to the return line bymeans of a passage 162. There is a similar passage 163 also connectedinto the return line 140 which, in the lower position of thisintermediate valve, is just below the land 152.

When the intermediate valve is elevated to its upper position, the poweroilto the passages 101 is cut olf from the passage 160 and is introducedto the passage 161 leading to the top of the main valve. Meanwhile, thebottom of the main valve is ported by the passage 160 to the lower valvespace 155, whence it can connect through the passage 163 to the returnline 140.

The main valve has a lower land 171, and an upper land 172. These areseparated by a valving passage 173. In the illustrated upper position ofthe main valve, the power oil through the passages 102 is cut off by thelower land 171, and the upper cylinder 71 is connected through thepassage 138 with the return line 89, which connects to the productionoil space by way of the passage 140. This means that the upper part ofthe hydraulic motor piston is at production oil pressure. Upon reversalof tthe intermediate valve 150, the main valve 170 will be drivendownwardly. This will cut off the passage 89 and connect the power oilpassage 102 with the cylinder passage 138 through the valve space 173.This will put power oil pressure onto the upper cylinder 71.

The top of the valve'body passage is closed by a sealing plug 175 thatalsoprovides an upper limit to the movement of the main valve.

Operation At the start, it is assumed that the power oil pipe 20 isconnected to some suitable source of pressure on the surface such as aform of ipump that can supply an adequate amount of oil under pressurefor the present purposes. As a result, the pressure in the powercylinder that is delivered from the power oil pipe 20 is the normalhydrostatic head of oil from the cylinder to the surface, plus whateverpressure isy superposed thereupon by thc pumping mechanism aforesaid.This pressure is constantly delivered from the power oil pipe 20 to thechamber 80, thence by the passage 81 to theV space 70 within the barrel22. From this space it descends all the way down to just above 'thesucker rod pump connection, whence it can enter through the holes 66into the lower cylinder 67 and act upwardly upon the effective lowerarea of the piston 37 which, as understood, equals the inside diameterof the cylinder or barrel 46 minus the outside diameter of theconnecting rod 31. This pressure acting upon the lower surface of thepiston thereby tends to move the piston upwardly, carrying with it theconnecting rod 31 which, in turn, is connected down to the sucker rodprojection 26 and ultimately to the sucker rod pump (not shown).

The foregoing is not to say that the mere existence of power oilpressure within the cylinder 67 `actually causes the piston to moveupwardly because of conditions to appear. Whether or not the pistonmoves upwardly depends upon the conditions set by the valve apparatus.

In the position of the valves illustrated in Figure 1l, themechanicalvalve 110 is in its neutral position, since it ibas ybeenactedupon andreleased. Its -la'st movement mum production oil unitpressure.

9. was downwardly, in which case it would have ported power oil from theport i) through the passage 144 to the upper valve chamber over theupper end of the intermediate valve 150. It correspondingly would haveported the lower valve chamber of the intermediate valve by way of thepassage 143 and the passage 142 to the production oil at relatively lowpressure, namely hydrostatic head of oil in the well. Since the poweroil is at higher pressure, such action would have driven theintermediate valve to its lower position illustrated.

The lower position of the intermediate valve 150 ports power oil fromthe passages `10ft to the passage 160 and to the lower valve actuatingchamber of the upper valve 170. At the same time, the upper actuatingpressure chamber of the main valve 170 is connected by the passage 1 61to the return passages 165 and 140. This accounts for the upper positionof the main valve 170 that causes the upper cylinder 71 to be ported tothe return line. This condition is illustrated by the fact that theupper cylinder 71 is in continuous communication through centeringspring'cage 48, spacer 50, and passage 140 to the passages 8S that areconnected into the well casing.

When the foregoing condition exists, the motor piston is acted on bypower oil pressure at its underside and well casing hydrostatic headpressure at its upper side. While the piston area on the lower side ofthe piston is less than that on the upper side, this is more thanovercome by the excess of power oil unit pressure over maxi-Consequently, the piston is driven upwardly.

In the illustrations, the piston has'recently begun its upward movement,carrying with it the sucker rod. To

show the greater pressure below the piston, the arrows pointing upwardin the cylinder 67 are solid; to show lesser pressure on greater area,the arrows pointing downward in the cylinder 71 are in 4broken lines butmore numerous. A

As the piston 37 goes upwardly, it will carry the overtravel spring cage39 upwardly with it, but it will not move the valve stem rod 120.Rather, it will reciprocate over that valve rod through substantiallythe whole stroke of the pump. This stroke may be in the order of fivefeet, for example. It is desirable to have suicient oil passage spacearound the valve stem parts to avoid great pressuredrop as the valvestem enters the oil-filled connecting rod and expels oil therefrom. Inthe illustrated design, the maximum pressure drop is about 2# as againstl0# inthe spring 126.

As the piston approaches the upper eXtreme of its movement, theactuator'41 'will constitute an abutment to impinge upon the bottom endof the connector 121, which is secured to the rod 120, and which acts asa companion abutment. Thereafter, any further movement of the piston rod(which movement will continue until there'is a reversing of the valves)will elevate the sleeve 125, and the valve stem 111 and the valve 110,moving the mechanical valve 110 to its upper position. In so doing, theupper end of the collar 121 abuts and elevates the lower centeringspring guide 126, elevating it against the spring 126. In the upperposition of the valve 110, as already noted, it ports power oil to thelower operating chamber of the intermediate valve 150 to elevate thatvalve, which, in turn, causes delivery of power oil to the upper side ofthe main valve 170 driving that valve downward. When the main valve 170is driven downward to its lower position, the cylinder 71 is connectedto power oil by'way of the passage 102. This means that power oil isintroduced by the passage 138 to the space below the valve body which isalways in communication with the lupper cylinder 71.

vWhen the foregoing takes'place, pressure is built up above the piston37 while, at the same time, the power oil pressure remains the samebelow the piston. Owing to the fact that the eiective area on the upperside of 1 'l0 the piston 37 is greater than that on the lower side, thisadmission of power oil pressure to the cylinder 71 causes the piston tostart rnc-ving downwardly. Immediately it causes the actuator 41 towithdraw from the collar 121 so that the neutralizing or centeringspring 126 may return the mechanical valve 110 to neutral position.However, the return of the valve `to neutral position merely provides ahydraulic lock on the intermediate valve, because in such position thelower actuating chamber of the intermediate valve is connected by way ofthe passage 143 to [the land 132 of the mechanical valve 110, at whichpoint it is blocked and trapped. At the same time, the upper operatingchamber of the intermediate valve is connected by the line 144 to theland 131 of .the mechanical valve 110, and is likewise hydraulicallylocked. By this arrangement, as soon as the mechanical pressure isrelieved from the mechanical valve 110, it forthwith effects a hydrauliclock to hold the intermediate valve in the position to which it justpreviously has been moved. It, of course, will be under- 'stood thatthere is no mechanical relief on the mechanical valve until the mainvalve is shifted, because it requires a shift of the main valve toreverse the conditions of the motor so as to reverse the direction ofmovement of the piston. Also, the intermediate valve 150 vis assured ofmovement to its full eXtreme before the hydraulic lock upon it isrendered effective. This will assure that, regardless of whether themechanical valve is again neutralized prior to full movement of the mainvalve 170, there will be full movement assured because of the positionof the intermediate valve.

The piston will then descend, and after the first brief part of itsmovement .the valve stem will not be moved, but the piston willreciprocate over the valve stem.

When the piston approaches the lower end of its movement on adownstroke, which is a position more or less as illustrated, it willcause the retainer 41 to approach the nut 123 which acts as an abutment.At the extreme of such downward movement, contact will be effectedbetween the retainer 41 and the nut 123, so that the subsequent smalldownward movement of the piston will cause the valve stern 120 to belowered from its neutral position, establishing the sequence ofreversing the action previously mentioned of all three valves, and againconnecting the cylinder 71 with the return line at production oilpressure, while leaving power oil pressure below the piston 37 so as toreverse the direction of the piston and drive it upwardly again. Afterthe rst brief pant of the upward movement of the piston as aforesaid,the mechanical valve will again be permitted to neutralize under theinfluence of the spring 126, providing the same hydraulic lock but with.the two upper valves in their opposite positions.

The foregoing represents the cycle of operation of the pump motor withitsV reversing valve apparatus. Since the pressure oil is always on theunderside of the piston, and since there is a differential piston area,with mechanical valve reversals, the piston cannot hang up on deadcenter, even though no springs are provided. If, for example, the pistonwere on an upstroke, and it partly shifted the valves until pressure ispartially admitted vinto the upper cylinder 71, a downstroke cycle isinevitable, because even the slowly entering pressure admitted through apartially shifted valve will ultimatelyV build up to provide thedownstroke. The main valve passage 173 should have an axial lengthinsufficient to connect the pressure passage 102 with the return passage89.

It is valuable to have the anti-stall feature, without springs. And thesame structure of the small upstroke area and `large downstroke areaprovides a relatively fast downstroke, which is the return stroke of thesucker pump.

Assembly Among the especial features of the present invention aredetails of the. arrangements for assembly and disassembly with minimumdifficulty and a minimum diversity of tools.

Reference has already been made to the adjustment between the spacer`tubes 24 and 241. The effect, which is accomplished by loosening the nut40 and relatively moving the two spacer tubes 24 and 241, is to shortenthe outer barrel of the pump at its lower end without shortening theconnecting rod 31. The overall result of this is to cause the pumppiston rod of the sucker pump to move closer to the end of the pumpingcylinder on the compression stroke. This has such advantages as theautomatic purging of the pump in the event of a vaporization of theliquid being pumped.

This adjustment is readily accomplished by putting awrench around thespacer tube 241 at the opposed flats 64, and another wrench around thenut 40 to loosen Ithe same. Thereafter, the two spacer tubes may berelatively twisted to get the proper extension or contraction of thelength, followed by tightening of the nut.

The reversing of the valve may be caused to occur only ait the extremeend of the movement of the pistonand hence of the sucker rod-by means ofthe adjustment of the two nuts 122 and 123, or of the collar 121.Normally, there is no need for adjustment of the collar 121 because itrepresents the relatively unadjustable upward movement of the mechanicalvalve 110.

It is fairly evident that the overtravel spring 40 will prevent anyundue strain on the parts should there be an overtravel before a shiftcan occur and in the event of maladjustment of sthe foregoing parts.

Ordinarily, in servicing the pump mechanism and motor, the rst thing tobe done is to separate the sucker rod pump from the hydraulic motor. Asthe equipment is raised to the surface, an appropriate itool may beslipped around the proposed flats 64 in the lower spacer tube 241, whichtube will extend outwardly so that the ap,- paratusV may be hung on thesurface superstructure of the well. Then the joint between the suckerrod pump 25 and the lower tubular extension 241 may be separated. Thepull rod 26 of the pump will remain attached to the` connecting rod 31by the coupling 30.

The preferable way to proceed for separation of the pull rod 26 is toloosen the lock nut 40 and separate the lower tubular extension 241 fromthe upper tube 2,4. Then if the pump piston is pulled downwardly, theextension tube 241 may move to expose the coupling 30 which then may beseparated from the tubular connecting rod 31. Thereupon, ithe sucker rodpump and the hydraulic motor are separated.

If it be desired then to service the inner mechanism of the pump, thepreferred procedure involves, lirst, a removal of the upper head 21 bythreading it out of the outer barrel 22. Thereupon, the lower couplingor packing retainer 23 can be removed and, if desired, drawn with anyparts below it that are attached to it, off the lower end of theconnecting rod 31, although this latter may not be necessary at thatpoint. Then, preferably, a tool is applied within the outer barrel 22 toforce outwardly upon the packing retainer and cylinder closure member43. Or the member 43 may be removed downwardly and the tool appliedagainst the inner barrel 46,

and also the rod 31. When these parts are pressedy upwardly, the innerbarrel 46 abuts against the centering spring retainer 48 which, in turn,abuts against the sleeve member S of the valve so that all of thoseparts together are forced out the upper end of the outer barrel 22 andemerged therefrom successively. In this operation, itis also preferredto force the connecting rod 31 upwardly,

because it is not removable from the valve stem 120 and' therefore wouldcause a separation of parts within-the pumping and valving sections ofthe mechanism.

If the servicing is to be done upon the valving elements, these alonemay be forced out the upper end of the outer barrel 2 2, and the valve,includingv its sleeve 55, withdrawn of the retainer 50. The mechanicalvalve does not necessarily move out with the valve body'. However, itmay readily be removed from the head of the extension 111 by slipping itlaterally through the slots 114 and 115, when the spacer retainer 50 ispulled away from it.

The successively lower parts may be serviced in like manner by beingforced out the upper end of the outer barrel 22. The retainer 50 may belifted out of the retainer 43. The mechanical valve operating mechanismmay be serviced by forcing the parts upwardly until the overcenterspring cage 39 projects and can be removed. This will free the lowercollar 123 for removal, whereupon the valve stem is freed and all of thepartsv may be removed, adjusted and serviced.

It is possible to separate the valve centering mechanism by removing thesetscrew holding the valve stem portion 120 in the collar 121.

The foregoing illustrates how the parts of this hydraulic motor pumpactuating means may be disassembled for servicing. The reassemblyconstitutes an obvious reversal of the disassembly above described. Itis also apparent how the various packing elements may be replaced indisassembly and reassembly process.

Thus, in general, there are three parts to the whole pump apparatus.There is the lower sucker rod pump subassembly not illustrated, butmerely represented inthe drawings. There is the hydraulic actuatingmotor, and there` is the control valve. The sucker rod pump can beremovedfrom the lower end of the actuating motor, and the valve can beremoved from the upper end of the actuating motor. Finally, theactuating motor itselfv may be. disassembled by being drawn out of itsbarrel.

By the foregoing description, it is not intended toV restrict the orderof assembly or disassembly, or to require that it be. through the upperend of the barrels other'than is obviously necessary from theconstructions involved. However, the fact that the assembly may be madelargely through the upper end of the barrel constitutes a valuablefeature. of this arrangement.

What is claimed is:

l. In a well pump: a power cylinder; a piston reciprocable therein andprovided with a tubular cage; valve means to control flow of fluid underpressure to the piston to effectv reciprocation of the piston, the valvemeans.

including a valve movable in the same directionsasithe piston; a valvestem coaxial with the piston and extendingv into the tubular cage of thepiston; first abuttable elements .on piston and stern within the pistoncomprising a ring-like retainer to be engaged at the end of a stroke invwhich the piston moves in a first direction to withdraw from' the stem,the elements preventing such withdrawal; second abuttable elements onpiston and stem comprising a collar tor be engaged at the end of anopposite stroke when thepiston moves in its second direction; andyieldable means including a spring surrounding the stem and yieldablyholding the retainer a maximum distance toward the collar so as toresistingly yield when the elements are abutted as aforesaid, to permitovertravel of the piston relatively to the valve.

2. The combination of claim l, wherein there are two such ring-likeretainers surrounding the stem and within the cage, constituting two ofthe abuttable elements; wherein the spring acts to separate them themaximum distance permitted by the cage; and wherein the retaineropposite the collar projects from the cage to engage with the otherabuttable element on the stem.

3. In a motor usable in a well for a reciprocable pump: a longV outertubular barrel; a head thereon having a power fluid passage leadingtherethrough to the inside of the barrclfadjacent-the wall-thereof, anda production fluid-passage leadingv from outside the upper part of thepump to the inside of the barrel at the middle part of the top; acylindrical valve device attached to the head to conn-ect the productionfluid passage into the valve and to separate off the power iluid passageto outside the valve; closure means at the lower end of the outerbarrel; an inner barrel within the outer barrel below the valve device;means connecting the upper end of the inner barrel and the valveproviding communication with the lower end of the valve device and theinside of the inner barrel, there being a power iluid space between theouter and inner barrel connecting with a space between the outer barreland valve device and with the power uid passage; ports through the innerbarrel adjacent the lower end; a piston in the inner barrel with aconnecting rod depending therefrom and extending through the closuremeans, the valve having means including a valve movable up and down, toalternately connect the upper side of the piston with the power uidpassage and the production uid passage, the piston having differentareas above and below; a Valve stern depending from the movable valveand into the piston; and two pairs of spaced abutment means between thevalve stem and the piston to cause movement of the valve when the pistonreaches the two extremes of its strokes.

4. The combination of claim 3, wherein the outer barrel is separablefrom the head and the lower closure; and wherein the valve device, theinner barrel, and the means connecting them are releasably clampedbetween the head and the lower closure, and may be ejected from the endof the outer barrel when the head is removed.

5. In a motor usable in a well for a reciprocable well pump: an outerbarrel; a removable barrel head; a removable lower barrel closure; avalve device in the barrel; an inner barrel containing a piston withinthe outer barrel; and means connecting the inner barrel and valve deviceand connecting means in axial alignment within the outer barrel to holdthem rigidly in place, and the aligned parts aforesaid being removablethrough the end of the outer barrel when the head and closure areremoved.

6. The combination of claim 5, with a valve stem depending from thevalve device to the piston, and spaced pairs of abutment elementsbetween the piston and stem to provide movement of the stem at the endsof the strokes of the piston.

7. The combination of claim 6, with the connecting means between thevalve device and the inner barrel comprising a centering spring cage; apair of axially spaced opposed xed abutments within the cage; and a pairof opposed, substantially equally spaced abutments on the stem, a pairof opposed spring guides surrounding the stem and a spring urging themapart, the gui-des being normally, yieldably engaged with the opposedabutments on the stem and fixed.

8. In a motor usable in a well for a reciprocable pump: an outer barrel;a motor cylinder and piston in the barrel; a connecting rod dependingfrom the barrel; a spacer tube device depending from the barrel aroundthe connecting rod; and connections for removably attaching a sucker rodpump at the bottom of the spacer tube device and for removably attachinga pull rod of the pump to the connecting rod of the motor, the spacertube device including telescopic adjusting parts by which the length ofthe spacer tube may be adjusted without changing the length of theconnecting rod and pull rod.

9. In a motor usable in a well for a reciprocable pump: an outer barrel;a motor cylinder and piston in the barrel; a connecting rod dependingfrom the barrel; a spacer tube device depending from the barrel aroundthe connecting rod; connections for removably attaching a sucker rodpump at the bottom of the spacer tube device and for removably attachinga pull rod of the pump to the connecting rod of the motor, the motorcylinder comprising an inner barrel separate from the outer barrel; avalve device above the inner barrel; and removable parts closing theends of the outer barrel, the pump and motor device being connectible byconnecting the tubular extension of the outer barrel to the pump and theconnecting rod to the pull rod, and the valve device and inner barrelbeing separable from the tubular extension upon removal of a removablepart for closing the end of the outer barrel.

l0. In a pump motor for a well: an outer barrel having means at itslower end for connection to a pump; a fluid cylinder and piston in theouter barrel providing uid pressure chambers above and below the piston;a valve device above the piston including a valve stem depending fromthe device, the stem extending down to the piston and being connectedagainst removal therefrom; one having a head and the other having alaterally open slot into which the head may be slipped to be heldagainst separation by axial forces; and means rigid with the barrel tohold the parts against lateral movement that would separate them.

References Cited in the file of this patent UNITED STATES PATENTS1,765,921 Joy June 24, 1930 2,039,570 Thornton May 5, 1936 2,060,180Davis Nov. 10, 1936 2,273,349 Farley et al Feb. 17, 1942

